Several common exposure modes of SLR cameras

The common exposure modes of single-lens reflex cameras are aperture priority (A), shutter priority (S), program automatic (P), manual mode (M) and preset mode. (1) Aperture priority exposure (a) Aperture priority exposure, also known as aperture priority automatic exposure, is generally represented by "A" on digital cameras. The photographer chooses the appropriate aperture, and the digital phase automatically matches the appropriate shutter speed to achieve accurate exposure. Aperture priority has two main functions: First, the shutter speed can be controlled through the aperture. Under the same illumination, the larger the aperture, the more light passes through the lens in unit time, so the shutter speed of digital camera will be faster, and vice versa. Using this feature, we can try to enlarge the aperture to get a faster shutter speed and prevent the photo from blurring due to hand shake when the shooting environment is poor and there is no tripod or other equipment to stabilize the camera. When the light in the shooting scene is too strong, the shutter speed required for a large aperture may exceed the maximum shutter speed limit of a digital camera. At this time, you can try to reduce the aperture to reduce the shutter speed of the digital camera. Secondly, in the aperture priority mode, you can also control the depth of field through the aperture. Not all scenes in a photo should be very clear, and sometimes we can achieve the purpose of highlighting the main body by blurring some minor scenes. The relationship between aperture and depth of field is: the larger the aperture, the shallower the depth of field, that is, the smaller the clear range in the picture; The smaller the aperture, the deeper the depth of field, that is, the larger the clear range in the picture. (2) Shutter priority (S) Shutter priority, also known as shutter priority automatic exposure, is generally represented by S on digital cameras. The photographer chooses the appropriate shutter speed, and the digital phase automatically matches the appropriate aperture size to achieve accurate exposure. This shooting mode is very suitable for taking photos of themes related to speed and movement, such as endless traffic, slow-moving streams, fast-running athletes, etc., and the same theme will have different effects under different shutter speeds and different aperture values. For example, if you want to show the splash of the same river, you can set the shutter speed faster, such as1/250 s; If you want to get a silky continuous effect, you should use a relatively low shutter speed and shoot with a tripod. When using the shutter priority mode, we should also pay attention to the following two issues: First, we should use the slow door in strong light, and the smallest aperture may not avoid overexposure, so we should add a reducing mirror to the camera. The second is to use a fast shutter when the light is dark. It is possible that the maximum aperture will still make the picture underexposed. In this case, you can try to use exposure compensation or adjust the sensitivity. If the effect is not ideal, you can only reduce the shutter speed. (3) Program automatic exposure (P) Program automatic exposure refers to the mode of automatically adjusting the camera aperture and shutter speed. Convenient and quick photography, convenient for others to take pictures of you. You can select all available shutter speeds and apertures of the camera by dialing the dial or buttons, and basically you can get acceptable exposure, which is similar to using aperture priority or shutter priority mode to some extent. (4) Manual mode (M) In manual mode, the shutter speed and aperture setting are controlled by the photographer himself. Usually, the camera will provide a graphic or digital display to remind you of the difference between the current exposure setting and the recommended exposure. A plus sign indicates that the exposure is higher than the recommended value, and a minus sign indicates that the exposure is insufficient. By setting different aperture and shutter combinations, many unusual effects can be obtained. This mode is often used in photography creation, which requires a higher photographer. In addition to the above modes, there are various preset modes suitable for beginners on digital cameras, including full-automatic or "green" mode, and preset values of scene shooting objects (such as portraits, landscapes, sports and night scenes). But these modes are not necessary, and the same effect can be achieved by controlling the aperture or shutter.